Stream: general

Topic: target_has_atomic


RalfJ (Aug 02 2019 at 17:59, on Zulip):

Is it correct that on 64bit x86, I cannot use AtomucU128? The compiler tells me there is no such type even when I set the feature flag.

RalfJ (Aug 02 2019 at 17:59, on Zulip):

Relatedly, does 32bit x86 have AtomucU64?

RalfJ (Aug 02 2019 at 18:00, on Zulip):

I am trying to write a test case for https://github.com/rust-lang/miri/issues/475 but I need some atomic type that actually is larger than the alignment its nonatomic version has anyway^^

RalfJ (Aug 02 2019 at 18:07, on Zulip):

Relatedly, does 32bit x86 have AtomucU64?

the answer seems to be yes

nagisa (Aug 02 2019 at 20:28, on Zulip):

Is it correct that on 64bit x86, I cannot use AtomucU128? The compiler tells me there is no such type even when I set the feature flag.

Double-size atomics should be available on x86

nagisa (Aug 02 2019 at 20:30, on Zulip):

But it appears that the targets specify max atomic as 64-bits, so there you have it.

RalfJ (Aug 02 2019 at 20:39, on Zulip):

so that's a bug in the x86 target specs?

nagisa (Aug 02 2019 at 20:54, on Zulip):

/me shrugs. Knowing that there’s double-wide cmpxchg on x86_64, I would expect atomics to work based on that.

Last update: Nov 20 2019 at 11:30UTC